The Science Behind Being Knocked Out
Knockouts happen because the brain isn’t completely glued to the skull; it has room for movement. A kick or punch to the jaw can displace it
For the most part, the brain is secured by blood vessels and nerves that are integrated between the skull and different layers of tissue
When the jaw is kicked with enough force, the brain and nerves reach a critical point where they can’t sustain consciousness
As the blood vessels get stretched out, they’re not able to sustain the continued blood supply the brain may need, and the person may black out immediately.
Via spacetimecontinumm